1. Technical Field
The invention relates to a velocity measurement system, and particularly to a system and method for measuring the direction and magnitude of the velocity of a target by performing frequency modulation of a laser output.
2. Description of the Related Technology
A number of systems and apparatuses have been developed for measuring the distance and velocity of an object using various methods.
As one example of the systems, U.S. Pat. No. 6,133,993 discloses “a length and velocity measurement apparatus.” The apparatus discloses using amplitude modulation (AM) and Doppler shift of carrier in order to measure velocity.
As another example of the systems, U.S. Pat. No. 6,317,073 discloses “FW-CW radar system for measuring distance to and relative speed of a target.” The system measures the speed and distance of the vehicle using a radar wave.
In addition to the above patents, many other U.S. patents, such as U.S. Pat. Nos. 6,311,121, 6,141,086, 5,164,784 and 3,915,572, etc., discuss methods for measuring speed of a target.